Driving vehicles while drowsy and falling asleep at the wheel are dangerous behaviors that cause car accidents, injuries, deaths, and monetary losses. Driving while drowsy or sleepy often garners comparisons to driving while chemically impaired (e.g., by alcohol) due to its disastrous consequences. However, while breathalyzer and blood tests are available to test for alcohol-impaired driving, tests to detect or determine whether a driver is driving while drowsy or sleepy are not readily available. Furthermore, self-reporting of drowsy and/or sleepy driving tends to be unreliable. As a result, drivers are not currently well-informed of the degree to which they are drowsy or sleepy, nor are drivers knowledgeable regarding their drowsy and/or sleepy driving habits, thus increasing the risk to them and others when they operate vehicles while drowsy or falling asleep.